How big is Anza-Borrego Desert State Park?

More than 600,000 acres, or roughly 1,000 square miles. It is the largest state park in California and the third largest in the United States, spanning parts of San Diego, Riverside and Imperial counties.

How much does it cost to enter Anza-Borrego?

Day use is $10 per vehicle, collected at the Visitor Center, developed campgrounds and several popular trailheads including The Slot and Hellhole Canyon. The park has no entrance gates and much of it can be accessed without a fee.

When is wildflower season at Anza-Borrego?

Annual wildflowers can appear from January through mid-April, with peak bloom most often between late February and early April. Timing varies year to year based on rainfall and temperature.

Is Anza-Borrego a Dark Sky Park?

Yes. The park was designated an International Dark Sky Park in 2018 at Silver tier. Borrego Springs, the town at its center, has been an International Dark Sky Community since 2009, the first in California.

Do I need four-wheel drive at Anza-Borrego?

Not for the paved roads, the Visitor Center or the main campgrounds. The vast majority of the park's roughly 500 miles of dirt roads do require a high-clearance four-wheel-drive vehicle.

Is Anza-Borrego Desert State Park open at night?

Yes, the park is open 24 hours a day, year-round. The Visitor Center is open daily 9am to 5pm October through May, and weekends and holidays only June through September.

Shandel Sutherland • September 11, 2023

The Marine Period of Anza-Borrego

Unveiling the Geological Marvels of Anza-Borrego State Park’s Marine Period

Anza-Borrego State Park, nestled within the Colorado Desert of Southern California, stands as a sprawling testament to nature’s grandeur. Encompassing over 600,000 acres, it reigns as California’s largest state park and ranks second in size among contiguous U.S. state parks. Its untamed terrain boasts deep canyons, towering peaks, and expansive deserts, alluring hikers, campers, and nature aficionados alike.

Yet, beneath this breathtaking landscape lies a hidden secret: it was once submerged beneath the ocean during an era known as the marine period. Millions of years ago, a vast inland sea, recognized as the Gulf of California, enveloped the region. This sea extended over much of what we now know as the southwestern United States. Over eons, the sea withdrew, leaving behind a treasury of captivating geological formations that grace Anza-Borrego State Park today.

Geological History:

The marine period of Anza-Borrego State Park unfolded between 23 and 5 million years ago, spanning the Miocene and Pliocene epochs. During this time, the region hosted the Gulf of California, an inland sea teeming with diverse marine life, including whales, dolphins, sharks, and giant sea turtles.

As the sea gradually retreated, it bestowed upon the land a profound geological legacy. Sedimentary rocks, fossils, and various geological formations now tell the tale of this bygone era.

Influences on the Landscape:

The marine period’s influence on Anza-Borrego State Park’s landscape is nothing short of spectacular. Here are some of the most prominent geological formations:

1. Fossil Beds: The park’s fossil-rich grounds house remnants of prehistoric creatures such as horses, camels, and other mammals. These fossil beds offer a glimpse into Earth’s evolutionary history.

2. Sea Caves: Erosion by ocean waves during the marine period carved out a series of sea caves, captivating relics of the past.

3. Badlands: Eroded slopes and vivid sedimentary rock layers define the park’s badlands. These formations resulted from the erosion of soft sedimentary rocks from the marine period.

4. Sand Dunes: The park’s expansive sand dunes formed from windblown sands deposited along the ancient sea’s shores, creating an ever-shifting landscape.

5. Faults: The marine period played a pivotal role in shaping the park’s topography, creating a complex network of faults and fractures. These tectonic forces continue to sculpt the park’s deep canyons and towering mountains.

6. Geothermal Features: Anza-Borrego State Park’s location on the San Andreas Fault contributes to its many hot springs and mud pots, where hot water and steam rise to the surface.

Exploring Anza-Borrego State Park:

Visitors to Anza-Borrego State Park can savor its geological wonders through various activities. Guided tours, including geology and paleontology tours, offer in-depth insights into the park’s captivating geology. Astronomy enthusiasts can partake in stargazing events, benefiting from the park’s remote location and minimal light pollution.

For a more relaxed experience, numerous picnic areas and campgrounds invite visitors to bask in the desert’s splendor. The park also hosts visitor centers and museums, providing opportunities to delve deeper into its geology, history, and wildlife.

Noteworthy Sites to Explore:

The Fossil Beds
The Slot Canyon
The Wind Caves
The Badlands
The Sand Dunes
The Borrego Palm Canyon
The Carrizo Badlands Overlook
The Yaqui Pass Interpretive Trail
The Font’s Point Overlook
The Anza-Borrego Desert Natural History Association bookstore and gift shop

Visit A Timeless Park:

The marine period of Anza-Borrego State Park stands as an enthralling chapter in Southern California’s geological history. Millions of years ago, this region was submerged beneath an ancient sea, leaving behind a treasure trove of geological marvels. Today, visitors have the opportunity to explore this rich history and witness the enduring beauty of this desert landscape.

Whether you’re a nature enthusiast, a geology enthusiast, or simply someone eager to explore new horizons, Anza-Borrego State Park beckons you to embark on a journey through time and geology. Don’t wait; plan your visit to Anza-Borrego State Park today and unlock the secrets of this captivating desert landscape!